情态动词 in class

would 情态动词 would 主要表示”愿意“， 其 次作为will 的过去式使用。
1. Would you like some tea? Yes, please. / No, thanks.
2. Would you like to join us? Yes, I’d like to.
3. Would you like me to help you with your English?
情态动词的特点：
1. 没有人称和数的变化。 He can _____ ( speak ) English.
2. 直接构成否定句，疑问句。 He can’t speak English. Can he speak English?
3. 必须和动词原形一起构成谓语。 He can speak English.
2. must 在肯定句中，表示“必须”，“一定 要”。 You must obey the traffic rules when driving in the city.
3. must 在否定句中，表示“千万不要”，“决 不可” “禁止”。 You mustn’t smoke here.
May I (we)…?
1.Because there is no light in the room, he _B____ be in.
A. mustn't B. can't C. needn't D. dare not
2.---May I smoke here? --- No, _A_______.
A. you mustn't B. you may not
• A. needn't to come B. don't need come
• C. don't need coming D. needn't come
情态动词 can, may, must, need, should, shall, will, could, would
1. The bird can sing sweet songs. 2. Can I help you? 3. May I leave the table now? No, you may not. 4. Must I do my homework at once? No, you needn’t. 5. You should apologize to Mr Hopkins. 6. Shall we go by ourselves? 7. Could you help Linda with her lessons later?
A: Must we keep quiet here? B: Yes, we must. A: Must we hand in the exercise books this afternoon? B: No, we needn’t. We may hand them in tomorrow. A: Can you spell the word “annoying”? B: Yes, I can. “a-n-n-o-y-i-n-g”. A: Can you tell me why we must do the exercises? B: Sorry, I can’t. You’d better go and ask the teacher yourself.
2) 情态动词：
can （ 可以， 会， 可能）
may （ 可以, 可能， 请求或建议）
may + V ( 对现在情况的推测 ）
may have done ( 对过去情况的推测）
must (必须， 应该，一定，大概， 2，3人称命令要求）
need : 1）need do sth / needn’t do sth 2）need to do sth don’t need to do sth
should ( 应该) ==ought to / had better would ( 主观意志和愿望）
have to 不得不，必须 be able to 可能， 能够 ought to 应该 used to 过去常常
don’t have to ==needn’t do sth
Must 用于一般疑问句，表示询问对方的意图。
can
1. Can (could) 表示一种能力。无论肯定还是否定， 都用can 来回答。 A: Can you play football?
B: Yes, I can. No, I can’t. 2. 在征询对方许可的疑问句首， 可用can也可用 may开问
A: Can I come in? / May I come in？
T: You should not be late next time.
In the reading room. A: May I have this seat? B: Yes, please. A: May I use your computer? B: Sorry, you can’t. I’m using it now. A: May I have some crackers here? B: No, you mustn’t. You should obey the rules.
may leave some to tomorrow.
A. can't B. mustn't C. don't D. needn't
• 5. You __D___ to the meeting this afternoon if you have something important to do.
肯定的回答只能是 must 否定的回答有两种：一定不行的用 mustn’t
没有必要用 needn’t.
1. A: Must I finish my homework before I play video games, Mum? B: I’m afraid you must.
2. A: Must I get up early tomorrow, Dad? B: No, you needn’t. Tomorrow is Sunday.
C. you'd better Could I use your pen? --- Certainly, you __B____.
A. will
B. can
C. may
D. could
4. --- Must we finish the work today? --- No, you _D_____. You
1 表示允许或征求对方的许可
肯定回答通常用 Yes, you may.
否定的回答有两种：不可以的: No, you may not;
2 表示请求或提出绝建对不议行的: No, you mustn’t. May I help you?
3. 可以表示可能性有“或许”、“ 可能 ” His grandparents may come tomorrow.
B: Yes, you can. / Yes, you may.
用Could 开问的句子不表示过去时， 只表示语 气的委婉，答句或后面的宾语从句都从现在时范 畴的时态考虑。 1. A: Could you help me with my lessons?
B: Of course I can.
2. Could you tell me if you have finished your work?
Yes, please. / That’s very kind of you.
No, thanks. / No, thank you. I can do it myself.
情态动词的表推测：
must +动词原形： 表示说话人对现有状态的肯 定猜测；意思是“一定是” Even the top students in our class can’t work out this problem, so it must be very difficult. He can’t be Mr. Brown. He has just gone to Europe. can’t +动词原形： 表示说话人对现有状态的否 定猜测；意思是“不可能”
(At the beginning of a class)
S for students T for teacher
S: May I come in ?
T: Yes, please.
S: Excuse me for my being late. There were so many cars on the road, and the taxi driver couldn’t drive fast.